Technical Field
This disclosure relates generally to motive power systems and more particularly to a method, system and process for improving efficiency by matching power to load requirements during motive vehicular use.
Background
For a typical moving vehicle at lower speed levels, rolling resistance is a predominant loss mechanism providing a nearly linear relationship between power increases and speed increases as shown in the typical power versus speed profile for a vehicle under an operating condition set forth in FIG. 1. At higher speed levels, air drag becomes a factor as well and those losses show a non-linear relationship. A well-accepted measure of vehicle fuel efficiency for automobiles is and has traditionally been “miles per gallon” (MPG). Since the shape of the curve in FIG. 1 is dominated by external factors, improvements have translated into increased fuel efficiency. Examples include improved aerodynamics to reduce high-speed drag and less vehicle weight to reduce rolling resistance.
FIG. 2 illustrates typical engine efficiency versus engine output power under an operating condition. A level of output power is required to maintain engine operation, a portion of which is used internal to the engine. Fuel injection has improved combustion control and, together with improved materials and manufacturing capability, has allowed equivalent power production in physically smaller engines, often with fewer cylinders. Resulting fuel efficiency improvements have been somewhat offset by pollution control requirements that typically reduce overall fuel efficiency.
Traditional automobile power systems are functionally depicted in FIG. 3, and have remained largely unchanged since the internal combustion engine (ICE) became the industry standard in the early 1900s. The inclusion of a fuel consuming auxiliary engine that (if operated in conjunction with a main engine) consumes fuel, in addition to the fuel consumed by a main engine, for selectively powering one or more devices or systems such as a pump, heater, generator or an air conditioner is known.
Traditional vehicle power systems similar to those depicted in FIG. 3 are a determinant to the fuel efficiency. FIG. 2 shows the typical efficiency of internal combustion engines as a function of said engine output power. Maximum efficiency is achieved as the engine approaches but at a point below maximum engine output power capability.
Definitions
Controller means a device that controls operation of a motor or other device by supplying the motor or other device with one or more control signals or electrical power forms. (Control signal or electrical power form characteristics that provide control can include but are not limited to voltage, current, frequency, phase, impedance, and duty factor).
Main Engine means the internal combustion engine that provided power for all loads of a conventional vehicle power system. A characteristic of a main engine is that its size and output is determined by the total peak power needs for a vehicle.
Motive Loads means a load directly related to providing power to vehicle wheels, propellers or props.
Non-Motive Loads means all loads that are not motive loads.
Engine Loads means a subset of non-motive loads internal to an engine.
Engine Support Non-Motive Loads means a subset of non-motive loads, which are external to the engine and support engine function.
Other Non-Motive Loads means a subset of non-motive leads which do not support engine function.
Auxiliary Subsystems means systems that produce other non-motive loads.
Engine Subsystems means systems that produce engine loads.
Engine Support Subsystems means systems that produce engine support non-motive loads.